Derivative Financial Instruments - Exposure to Credit Loss on Call Options Held (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Fair Value	$ 546	$ 849
Not Designated as Hedging Instrument \| Call options
Derivatives, Fair Value [Line Items]
Notional Amount	23,297	19,404
Fair Value	244	816
Collateral	219	790
Net Credit Risk	33	42
Not Designated as Hedging Instrument \| Call options \| Merrill Lynch
Derivatives, Fair Value [Line Items]
Notional Amount	3,563	3,307
Fair Value	23	128
Collateral	0	86
Net Credit Risk	23	42
Not Designated as Hedging Instrument \| Call options \| Morgan Stanley
Derivatives, Fair Value [Line Items]
Notional Amount	1,699	2,184
Fair Value	14	86
Collateral	19	92
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Barclay's Bank
Derivatives, Fair Value [Line Items]
Notional Amount	6,049	5,197
Fair Value	65	231
Collateral	59	233
Net Credit Risk	6	0
Not Designated as Hedging Instrument \| Call options \| Canadian Imperial Bank of Commerce
Derivatives, Fair Value [Line Items]
Notional Amount	5,169	2,936
Fair Value	68	147
Collateral	64	151
Net Credit Risk	4	0
Not Designated as Hedging Instrument \| Call options \| Wells Fargo
Derivatives, Fair Value [Line Items]
Notional Amount	1,361	2,445
Fair Value	17	89
Collateral	17	90
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Goldman Sachs
Derivatives, Fair Value [Line Items]
Notional Amount	1,133	307
Fair Value	9	10
Collateral	10	10
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Credit Suisse
Derivatives, Fair Value [Line Items]
Notional Amount	1,039	1,485
Fair Value	5	74
Collateral	5	75
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Truist
Derivatives, Fair Value [Line Items]
Notional Amount	2,489	1,543
Fair Value	35	51
Collateral	36	53
Net Credit Risk	0	$ 0
Not Designated as Hedging Instrument \| Call options \| Citibank
Derivatives, Fair Value [Line Items]
Notional Amount	795
Fair Value	8
Collateral	9
Net Credit Risk	$ 0

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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Nominal or face amount used to calculate payment on derivative.

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